The present invention relates to a spacer profile for an insulated glazing unit, which profile has a cross-section based on a rectangular shape, is provided with two parallel spaced side walls which, when said insulated glazing unit is assembled, will be placed against the panes of glass to be kept apart from each other, and is further provided with first and second transverse walls which extend between said side walls and of which the first will be adjacent to the edge of the glazing unit and the second will face the space between the panes. By the use of sealants, the space formed between the panes of glass is sealed from the edge of each pane, and the use of a desiccant ensures that said space is kept dry and thus remains free from fogging.
Spacer profiles are frequently used in the form of hollow profiles of metal (stainless steel or aluminum). The profile has two parallel side walls, against which the panes of glass will bear and two transverse walls extending between the side walls in the form of legs, which are substantially at right angles to the side walls of the hollow profile and join them together.
With regard to their bonding strength relative to conventionally employed sealants and their impermeability to the water vapor penetrating from outside into the space between the panes, they meet the demands, but the heat flow near the edges of the panes is excessive on account of the metallic materials used. Even when the space between the panes is filled with a noble gas, such as xenon or krypton, a serious drop in the insulating value, especially in the marginal regions, is observed.
Improvement as regards thermal insulation in the marginal areas of insulated glazing units has been achieved by the proposals made in DE-A 33 02 659, DE-A 127 739, EP-A 0 430 889, EP-A 0 601 488, DE-A 198 05 348, DE-U 298 147 68 and DE-A 198 07 454, which make use of plastics material instead of metallic materials and in some cases use metallic vapor barrier films or metallic reinforcing elements in the side walls and legs and embed the same in the plastics material.
Just as with spacer profiles of metal, spacer profiles of plastics material must still be filled with necessary desiccants when assembling a spacer frame, in order to lower the tendency of the insulated glazing unit to fog.
Depending on the air humidity conditions during filling, the drying agents take up more or less large quantities of water vapor from the production environment while the spacer frame is being filled and are thus incorporated in the final sealed insulated glazing unit with only a fraction of their capacity to bind water vapor for drying, or keeping dry, the space between the panes.
It is an object of the present invention to provide a spacer profile for insulated glazing units which is simple to handle when the spacer frame is being assembled whilst a higher absorption capacity for water vapor is retained by simple means.